记开发个人图书收藏清单小程序开发（五）Web开发

决定先开发Web端试试。

新增Web应用：

选择ASP.NET Core Web Application，填写好Name和Location，然后点击OK。

注意红框标出来的，基于.NET Core 2.1版本。登录认证用了微软自带的Identity。Template选择Web Application，也即最新的Razor Pages试图引擎模式。

创建完毕，因为该Template自带的bootstrap还是3.3.7，所以从中文网站下载最新的bootstrap 4.x，同时还需要下载的是popper js插件（如果用到dropdown组件的话，不大明白为何新版Bootstrap不自带这个）。_Layout中的css和js引用也需要同步更新一下，还有就是Navbar菜单需要更新，因为3.x和4.x用的class样式完全不一样。

下面给出示例代码：

<nav class="navbar navbar-expand-lg navbar-light bg-light fixed-top">
    <div class="container">
        <a asp-page="/Index" class="navbar-brand">PTager Shelves</a>
        <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
            <span class="navbar-toggler-icon"></span>
        </button>

        <div class="collapse navbar-collapse" id="navbarSupportedContent">
            <ul class="navbar-nav mr-auto">
                <li class="nav-item active">
                    <a class="nav-link" asp-page="/Index">Home</a>
                </li>
                <li class="nav-item">
                    <a class="nav-link" asp-page="/About">About</a>
                </li>
                <li class="nav-item">
                    <a class="nav-link" asp-page="/Contact">Contact</a>
                </li>
            </ul>
            <partial name="_LoginPartial" />
        </div>
    </div>
</nav>

到此，Web项目基本改造完成了。

当然，前面说到我还是用PTager的现有的登录DB做登录功能，很简单，直接修改appsettings.json文件中的DB连接字符串就好了（如果没有也没事，直接用本地的空DB，注册的时候会提示如何自己创建DB）。

{
  "ConnectionStrings": {
    "DefaultConnection": "Server=.\SQL2017;Database=PTager;Trusted_Connection=True;MultipleActiveResultSets=true"
  },
  "Logging": {
    "LogLevel": {
      "Default": "Warning"
    }
  },
  "AllowedHosts": "*"
}

开始新增New Book功能。

先check豆瓣图书的api能不能正常调用。

在Pages文件夹下New Folder：Shelves，继续在Shelves文件夹New Item=>Razor Pages，Name直接改为：New。

为了接受豆瓣图书API获取的参数信息，先定义一个DoubanBookModel：

    public class DoubanBookModel
    {
        public string title { get; set; }
        public string subtitle { get; set; }
        public IEnumerable<string> author { get; set; }
        public IEnumerable<string> translator { get; set; }
        public string isbn13 { get; set; }
        public string isbn10 { get; set; }
        public string author_intro { get; set; }
        public string summary { get; set; }
        public string publisher { get; set; }
        public string binding { get; set; }
        public string origin_title { get; set; }
        public int pages { get; set; }
        public string image { get; set; }
        public string pubdate { get; set; }
        public string catalog { get; set; }
        public IEnumerable<TagItem> tags { get; set; }
        public RatingItem rating { get; set; }


        public sealed class TagItem
        {
            public int count { get; set; }
            public string name { get; set; }
            public string title { get; set; }
        }
        public sealed class SeriesItem
        {
            public int id { get; set; }
            public string title { get; set; }
        }
        public sealed class RatingItem
        {
            public int max { get; set; }
            public int min { get; set; }
            public int numRaters { get; set; }
            public string average { get; set; }
        }
    }

/Pages/Sheves/New.cshtml：

@page
@model NewModel
@{
    ViewData["Title"] = "New Book";
}
<nav aria-label="breadcrumb">
    <ol class="breadcrumb">
        <li class="breadcrumb-item"><a asp-page="/Index">Home</a></li>
        <li class="breadcrumb-item"><a asp-page="/My Books/Index">My Books</a></li>
        <li class="breadcrumb-item active" aria-current="page">New Book</li>
    </ol>
</nav>
<form method="get">
    <div class="input-group input-group-lg mb-3">
        <div class="input-group-prepend">
            <span class="input-group-text" id="basic-addon1">ISBN #</span>
        </div>
        <input name="isbn" class="form-control" autofocus autocomplete="off" placeholder="ISBN #">
        <div class="input-group-append">
            <button class="btn btn-secondary btn-lg" type="submit">Search</button>
        </div>
    </div>
</form>
<hr />
@if (Model.DoubanBook != null)
{
    var item = Model.DoubanBook;
    <div class="media">
        @*<img class="align-self-start mr-3" src="@item.image" alt="Generic placeholder image">*@
        <div class="media-body">
            <h3 class="mt-0">@item.title<small class="ml-3">@item.subtitle</small></h3>
            <p><strong>Origin Title: </strong> @item.origin_title</p>
            <p><strong>Author: </strong> @string.Join("、", item.author)</p>
            <p><strong>Translator: </strong> @string.Join("、", item.translator)</p>
            <p>
                <strong>Pubdate: </strong> @item.pubdate
                <strong class="ml-3">Publisher: </strong> @item.publisher
                <strong class="ml-3">Binding: </strong> @item.binding
                <strong class="ml-3">Pages: </strong> @item.pages
            </p>
            <p>
                <strong>ISBN: </strong> @item.isbn13
            </p>
            <p><strong class="mr-3">Author Intro:</strong> @item.author_intro</p>
            <p><strong class="mr-3">Summary:</strong>@item.summary</p>
            @foreach (var tag in item.tags)
            {
                <span class="badge badge-info">@tag.name</span>
            }
        </div>
    </div>
    <hr />
    <form method="post">
        <input type="hidden" asp-page="IsbnNbr">
        <button class="btn btn-warning" type="submit">Add To My Books</button>
    </form>
}

/Pages/Sheves/New.cshtml.cs：

    public class NewModel : PageModel
    {
        [BindProperty]
        public string IsbnNbr { get; set; }
        public DoubanBookModel DoubanBook { get; set; }

        public async Task OnGetAsync(string isbn)
        {
            IsbnNbr = isbn?.Trim() ?? string.Empty;
            if (validIsbnNbr(IsbnNbr))
            {
                DoubanBook = await getDoubanBook();
            }
        }
        private async Task<DoubanBookModel> getDoubanBook()
        {
            var url = $"https://api.douban.com/v2/book/isbn/:{IsbnNbr}";
            var result = await HttpGetAsync(url);
            return JsonConvert.DeserializeObject<DoubanBookModel>(result);
        }
        public async Task<string> HttpGetAsync(string url, Encoding encoding = null)
        {
            using (var httpClient = new HttpClient())
            {
                return await httpClient.GetStringAsync(url);
            }
        }

        private bool validIsbnNbr(string isbn)
            => !string.IsNullOrEmpty(IsbnNbr) && (IsbnNbr.Length == 10 || IsbnNbr.Length == 13);
    }

好了，现在可以直接从豆瓣图书API获取到返回结果了，并且能展示在页面：